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桂林地区降水及盘龙洞滴水和现代碳酸盐的氧碳同位素研究表明 :( 1 )从年内和年际的总体特征看 ,桂林地区降雨的δ18O值随着气温的升高和降雨量的增加而减小 ,就相关关系来看 ,与月均气温的相关关系更好 .但夏季风降雨的δ18O值要比冬季风降雨的δ18O值小得多 ;( 2 )洞穴滴水的δ18O明显与同期降雨的δ18O值成很好的相关关系 ;( 3)条件适宜时 ,δ13 C可以作为环境替代指标 ,即δ13 C值越负 ,C3 植物的比例就越大 ,降雨可能较丰沛 ,相反则可能以C4植物为主或为植被被破坏(由于气候原因或人为原因所导致 )后的石漠化环境 .
The results show that: (1) From the overall characteristics of year and interannual, the δ18O value of precipitation in Guilin area increases with the increase of temperature and rainfall And the correlation with the monthly mean temperature is better, but the δ18O value of summer monsoon rainfall is much smaller than the δ18O value of winter monsoon rainfall. (2) The δ18O of cave drip is obviously different from that of the same period of rainfall (3) δ13C can be used as a proxy for environmental conditions when the conditions are appropriate, that is, the more negative δ13C values, the greater the proportion of C3 plants and the more abundant precipitation. The contrary, the C4 plants Or mainly because of the desertification environment after the vegetation is damaged (due to climatic or human factors).